This invention relates to plasma acceleration.
Various plasma accelerators that take advantage of the Hall effect have been disclosed in U.S. Patents including, for example, U.S. Pat. No. 5,847,493 (Yashnov et al., Dec. 8, 1998), and U.S. Pat. No. 5,751,113 (Yashnov et al., May 12, 1998), and U.S. Pat. No. 5,845,880 (Petrosov et al., Dec. 8, 1998), with different distributions of the magnetic field.
Other configurations for plasma acceleration devices have been disclosed in a number of U.S. Patents such as U.S. Pat. No. 4,010,396 (Ress and Nolde, Mar. 1, 1977), U.S. Pat. No. 4,913,030 (Reynolds, Apr. 3, 1990); U.S. Pat. No. 5,291,734 (Sohnly, Mar. 8, 1994); U.S. Pat. No. 5,892,329 (Arkhipov, Apr. 6, 1999); U.S. Pat. No. 5,581,155 (Morozov et al., Dec. 3, 1996); U.S. Pat. No. 5,869,428 (Fruchtman, Jan. 12, 1999); U.S. Pat. No. 5,798,602 (Gopanchuk and Sorokin, Aug. 25, 1998); U.S. Pat. No. 5,435,900 (Gorokhovsky, Jul. 25, 1995); U.S. Pat. No. 5,389,195 (Ouderkirk et al., Feb. 14, 1995); U.S. Pat. No. Re. 34,806 (Cann, Dec. 13, 1994); and U.S. Pat. No. 4,370,176 (Bruel, Jan. 25, 1983) which disclose various positions and directions for the magnetic fields and electrical fields, channel configurations, inductor arrangements, and vacuum insulator/isolator structures.
U.S. Pat. No. 5,750,205 (Shashkovsky et al., May 12, 1998) discloses an erosion type coaxial plasma accelerator for application of surface treatments on metallic substrates. U.S. Pat. No. 5,773,787 (Turchi, Jun. 30, 1998) discloses use of a pulsed plasma flow to displace magnetic flux, thereby inducing high voltages across multi-turn coils placed near the end of a coaxial gun.
However, there is still a need for plasma accelerators with higher particle flux per unit of power and which are more efficient while using electrical potentials to achieve a steady-state or pulsed acceleration of the plasma.
Therefore, it is an object of this invention to provide a plasma accelerator and a method of accelerating plasma particles.
It is another object of this invention to provide a plasma accelerator with higher particle flux per unit of power.
It is a further object of this invention to provide a plasma accelerator which allows axial acceleration of plasma mass by different electrical potentials.
It is yet another object of this invention to provide a plasma accelerator which can provide steady-state or pulsed acceleration of a plasma.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, there has been invented an apparatus for acceleration of a plasma having coaxially disposed cylindrical electrodes which have output end or nose additions of mesh screen shaped to converge (for a positive polarity inner electrode) or diverge (for a negative polarity inner electrode) to achieve improved particle flux per unit of power.